DOI

Because of its exceptional lithium storage capacity, silicon is considered as a promising candidate for anode material in lithium-ion batteries (LIBs). In the present work, we demonstrate that methods of soft X-ray emission spectroscopy can be used as a powerful tool for the comprehensive analysis of the electronic and structural properties of lithium silicides LixSi forming in LIB's anode upon Si lithiation. On the basis of density functional theory and molecular dynamics simulations, it is shown that the coordination number of Si atoms in LixSi decreases with an increase in Li concentration both for the crystalline and amorphous phases. In amorphous a-LixSi alloys, Si tends to cluster, forming Si-Si covalent bonds even at the high lithium concentration. It is demonstrated that the Si-L2,3 emission bands of the crystalline and amorphous LixSi alloys show different spectral dependencies, reflecting the process of disintegration of Si-Si network into Si clusters and chains of the different sizes upon Si lithiation. The Si-L2,3 emission bands of LixSi alloys become narrower and shift toward higher energies with an increase in Li concentration. The shape of the emission band depends on the relative contribution of the X-ray radiation from the Si atoms having different coordination numbers. This feature of the Si-L2,3 spectra of LixSi alloys can be used for the detailed analysis of the Si lithiation process and LIB's anode structure identification.

Translated title of the contributionЛитиевые продукты кремниевого анода на основе мягкой рентгеновской эмиссионной спектроскопии
Original languageEnglish
Pages (from-to)11096-11108
Number of pages13
JournalJournal of Physical Chemistry C
Volume122
Issue number20
DOIs
StatePublished - 24 May 2018

    Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physics and Astronomy(all)
  • Surfaces, Coatings and Films
  • Physical and Theoretical Chemistry

    Research areas

  • LITHIUM-ION BATTERIES, SPACE GAUSSIAN PSEUDOPOTENTIALS, CRYSTALLINE SILICON, ELECTROCHEMICAL LITHIATION, AMORPHOUS-SILICON, 1ST PRINCIPLES, MOLECULAR-DYNAMICS, ELECTRONIC-STRUCTURE, STRUCTURAL-CHANGES, NANOWIRE ANODES

ID: 35816026